Acid-Base

Question 1

What is the normal pH range of blood?

Answer 1

7.35-7.45

Question 2

What is the normal range of pCO2 in the blood?

Answer 2

4.7-6.0kPa

Question 3

What is the normal range of bicarbonate in the blood?

Answer 3

22-30mmol/l

Question 4

What is the normal range of bicarbonate?

Answer 4

22-30mmol/l

Question 5

What is the normal range of pO2 in the blood?

Answer 5

10-13kPa

Question 6

State three causes of a metabolic acidosis

Answer 6

Increased lactate, increased ketones (e.g. DKA), renal tubular acidosis, intestinal fistula, toxins

Question 7

State three causes of a metabolic acidosis

Answer 7

Increased lactate (e.g. DKA), renal tubular acidosis, intestinal fistula

Question 8

Describe the blood results in metabolic alkalosis

Answer 8

Increased pH, increased bicarbonate, normal or increased pCO2

Question 9

State three causes of a metabolic alkalosis

Answer 9

Pyloric stenosis, hypokalaemia, ingestion of bicarbonate

Question 10

Describe the blood results in respiratory acidosis

Answer 10

Decreased pH, normal or increased bicarbonate, increased pCO2

Question 11

State two causes of a respiratory acidosis

Answer 11

Lung injury (e.g. pneumonia, COPD), decreased ventilation (e.g. morphine OD)

Question 12

Describe the blood results in respiratory alkalosis

Answer 12

Increased pH, normal or decreased bicarbonate, decreased pCO2

Question 13

State two causes of respiratory alkalosis

Answer 13

Mechanical ventilation, hyperventilation (e.g.panic attack)

Question 14

What is a normal anion gap in serum?

Answer 14

14-18mmol/l

Question 15

How is the anion gap calculated?

Answer 15

(Na + K) - (Cl - HCO3)

Question 16

State the four main causes of metabolic acidosis with a raised anion gap

Answer 16

Ketoacidosis (DKA, alcohol, starvation)
Uraemia (renal failure)
Lactic acidosis
Toxins (ethylene glycol, methanol, paraldehyde, salicylate)

Question 17

How is the osmolar gap calculated?

Answer 17

Osmolality (measured) - osmolarity (calculated)

Question 18

What is a normal osmolar gap in the serum?

Answer 18

<10

Question 19

State four causes of an increased osmolar gap

Answer 19

Alcohols, mannitol, ketones, lactate, advanced CKD